diff options
| author | Will Deacon <will.deacon@arm.com> | 2019-04-10 11:51:54 +0100 |
|---|---|---|
| committer | Will Deacon <will.deacon@arm.com> | 2019-04-26 13:57:55 +0100 |
| commit | 427503519739e779c0db8afe876c1b33f3ac60ae (patch) | |
| tree | adb1c420287cb4a6fe1e84b098ef51eb61d964a0 | |
| parent | 8e4e0ac02b449297b86498ac24db5786ddd9f647 (diff) | |
futex: Update comments and docs about return values of arch futex code
The architecture implementations of 'arch_futex_atomic_op_inuser()' and
'futex_atomic_cmpxchg_inatomic()' are permitted to return only -EFAULT,
-EAGAIN or -ENOSYS in the case of failure.
Update the comments in the asm-generic/ implementation and also a stray
reference in the robust futex documentation.
Signed-off-by: Will Deacon <will.deacon@arm.com>
| -rw-r--r-- | Documentation/robust-futexes.txt | 3 | ||||
| -rw-r--r-- | include/asm-generic/futex.h | 8 |
2 files changed, 7 insertions, 4 deletions
diff --git a/Documentation/robust-futexes.txt b/Documentation/robust-futexes.txt index 6c42c75103eb..6361fb01c9c1 100644 --- a/Documentation/robust-futexes.txt +++ b/Documentation/robust-futexes.txt @@ -218,5 +218,4 @@ All other architectures should build just fine too - but they won't have the new syscalls yet. Architectures need to implement the new futex_atomic_cmpxchg_inatomic() -inline function before writing up the syscalls (that function returns --ENOSYS right now). +inline function before writing up the syscalls. diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h index fcb61b4659b3..8666fe7f35d7 100644 --- a/include/asm-generic/futex.h +++ b/include/asm-generic/futex.h @@ -23,7 +23,9 @@ * * Return: * 0 - On success - * <0 - On error + * -EFAULT - User access resulted in a page fault + * -EAGAIN - Atomic operation was unable to complete due to contention + * -ENOSYS - Operation not supported */ static inline int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr) @@ -85,7 +87,9 @@ out_pagefault_enable: * * Return: * 0 - On success - * <0 - On error + * -EFAULT - User access resulted in a page fault + * -EAGAIN - Atomic operation was unable to complete due to contention + * -ENOSYS - Function not implemented (only if !HAVE_FUTEX_CMPXCHG) */ static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, |